Positioning:
A specialized technical reference for automotive professionals, restorers, and enthusiasts engaged in precise bodywork or frame alignment on the early Porsche 928.
Competition:
Few aftermarket manuals delve into such granular dimensional data. This is a factory-level document.
Features:
Provides the definitive factory specifications for dimensional accuracy, essential for authentic restorations and high-quality body repairs.
Restoration Value:
Invaluable for owners undertaking concours restorations or ensuring factory-correct panel gaps and alignment, crucial for the car's aesthetic and structural integrity.
Primary Coverage:
Dimensions and Tolerances
Secondary Coverage:
Structural measurements, component alignment, body panel gaps, engine and chassis component mounting points
Estimated Page Count:
Varies based on original factory publication, typically 50-150 pages for such specialized manuals.
Type:
Technical Data Book / Dimensional Reference Manual
Language:
English (likely translated from original German)
Body And Chassis:
Exact body panel dimensions, frame measurements, chassis alignment points, door, hood, and trunk gap specifications, bumper alignment.
Engine And Powertrain Mounting:
Engine block and transmission mounting point locations and tolerances, subframe alignment, suspension component mounting dimensions.
Glass And Trim:
Windshield, rear window, and side glass installation dimensions, molding and trim alignment specifications.
Wheel And Tire Mounting:
Wheel mounting face dimensions, hub centering specifications, and potentially tire clearance measurements related to body fitment.
Interior Component Placement:
Dimensions related to the precise placement of dashboard components, center console, seats, and door panels for correct fit and alignment.
Measurement Techniques:
Guidance on utilizing measuring tools and techniques for verifying dimensions and tolerances.
Alignment Verification:
Procedures for checking and adjusting chassis, body, and component alignment against factory specifications.
Component Fitting:
Specifications for ensuring components like fenders, bumpers, and trim pieces are fitted within acceptable dimensional tolerances.
Depth:
Highly specific, precise measurements critical for factory-level body repair, restoration, and quality control. Not intended for general maintenance or troubleshooting.
Accuracy Requirement:
Requires precision measurement tools (calipers, measuring tapes, dial indicators) and a controlled environment for accurate verification.
Format Details:
Printable book format, likely with line drawings and tables.
Usage:
Primarily used by body shop technicians, restoration specialists, and engineers verifying assembly accuracy.
Quality:
Original factory print quality, designed for technical accuracy.
Binding:
Likely a stapled or perfect-bound booklet.
Paper:
Durable, matte paper suitable for technical documentation.
Engine Type:
Naturally aspirated V8 (M28/x series)
Displacement:
4.5 Liters (4474 cc) for early models (1978-1979). 4.7 Liters (4664 cc) introduced for 1980 onward (though this manual focuses on the early years).
Horsepower 1978 79:
Approx. 219 hp (163 kW) DIN
Torque 1978 79:
Approx. 281 lb-ft (381 Nm) DIN
Fuel Delivery:
Bosch K-Jetronic (CIS) Fuel Injection
Head Design:
Aluminum alloy, dual overhead camshafts (DOHC) per bank, 2 valves per cylinder.
Engine Placement:
Front-mounted, water-cooled V8
Transmission Type Standard:
5-speed manual transaxle
Transmission Type Optional:
3-speed automatic transaxle (e.g., by ZF)
Transaxle Layout:
Rear-mounted transaxle (engine in front, transmission in rear) for 50/50 weight distribution.
Length 1978 80:
Approx. 4550 mm (179.1 in)
Width 1978 80:
Approx. 1725 mm (67.9 in)
Height 1978 80:
Approx. 1280 mm (50.4 in)
Wheelbase 1978 80:
Approx. 2400 mm (94.5 in)
Curb Weight Manual:
Approx. 1450 kg (3197 lbs)
Curb Weight Automatic:
Approx. 1500 kg (3307 lbs)
Interior Space:
Designed as a 2+2 grand tourer, offering comfortable seating for two adults and occasional seating for two smaller individuals or children in the rear.
Trunk Volume:
Rear hatch provides substantial cargo space, configuration of which is not directly detailed in a dimensions/tolerances book but is part of the overall design.
Crash Test Ratings:
No standardized crash test ratings equivalent to modern NCAP available for this era.
Braking System:
4-wheel disc brakes (ventilated front), Anti-lock Braking System (ABS) became available later, not standard on early models.
Restraints:
Three-point seat belts, padded dashboard and steering wheel.
Audio System:
Period-appropriate cassette player and radio, often with high-quality (for the era) speaker systems.
ABS Availability:
ABS was an optional extra on later models of this generation, not a standard feature.
Connectivity Features:
No modern connectivity features (Bluetooth, USB, etc.) available. Analog systems only.
Oil Change Interval:
Typically every 15,000 km (9,000 miles) or 12 months, whichever comes first (refer to specific owner's manual for exact dates).
Timing Belt Replacement:
Timing belt replacement is critical. Intervals vary by year and type, but typically around 60,000-100,000 km (36,000-60,000 miles) or 4-6 years. This manual would not cover this, but it's crucial knowledge for owner.
Engine Oil:
SAE 20W-50 or 10W-40 (API SG or better, or specific Porsche approval A40/C3 for modern equivalents if used).
Transmission Fluid Manual:
GL-4 or GL-5 gear oil, viscosity typically SAE 75W-90 or 80W-90.
Transmission Fluid Automatic:
Dexron II or equivalent automatic transmission fluid (ATF).
Coolant:
Porsche Approved Antifreeze/Coolant, typically a 50/50 mix with distilled water.
Brake Fluid:
DOT 3 or DOT 4 brake fluid (e.g., ATE TYP 200 or equivalent).
Common Issues Early Models:
Fuel system (K-Jetronic components), electrical gremlins, potential head gasket leaks, interior material degradation, clutch wear (manual).
Heritage Context:
Porsche, renowned for its sports car engineering, introduced the 928 as a more luxurious, front-engined grand tourer, moving away from its rear-engined sports car legacy.
Evolution Summary:
The 928 was a revolutionary model for Porsche, featuring a transaxle layout, V8 engine, and a focus on GT comfort and performance. It evolved significantly throughout its production run.
Production Years:
1978-1995
Manufacturing Location:
Stuttgart, Germany
